Analyzing and Determining Subsitution Reactions Through SN1 & SN2 reactions involving Alcohol-Containng Compounds to verify production and succsess of alkyl halides. *Harpravjeet Malhi, Robert Sorg, Heather Reeves Department of Chemistry and Chemical Biology, IUPUI, 402 N. Blackford St., Indianapolis, IN 46202 hmalhi@imail.iu.edu This experiment was ran to stimulate real life application scenarios in which products were determined through various techniques learned from the past. Requiring analytical thinking and preparation, as a product was synthesized within the right time frame, with limited amount of starting material. The three compounds shown above are reacted with various reagents, to yield the best halide-containing product. These reactions are conducted to test the prediction that reaction 1 proceeded through a bimolecular nucleophillic substitution (SN2) and reactions 2 and 3, went through unimolecular nuclephillic substitution (Sn1), due to carbocation rearrangements forming 2 products each through a stepwise process. Conducting various tests through separation and purification methods can test the reactions and their hypothesized pathway, also Analyzing data through infrared spectroscopy (IR), proton nuclear magnetic resonance (1H NMR) and gas chromatography (GC) can give a final overall picture to the synthesized product, along with purity of the product and efficiency of the reactions. Throughout these experiments many important features of substitution
The objective of this lab was to create a ketone through an oxidation reaction using a using a secondary alcohol and oxidizing agent in order to use that ketone in a reduction reaction with a specific reducing agent to determine the affect of that reducing agent on the diastereoselectivity of the product. In the first part of this experiment, 4-tert-butylcyclohexanol was reacted with NaOCl, an oxidizing agent, and acetic acid to form 4-tert-butylcyclohexanone. In the second part of this experiment, 4-tert-butylcyclohexanone was reacted with a reducing agent, either NaBH4 in EtOH or Al(OiPr)3 in iPrOH, to form the product 4-tert-butylcyclohexanol. 1H NMR spectroscopy was used to determine the cis:trans ratio of the OH relative to the tert-butyl group in the product formed from the reduction reaction with each reducing agent. Thin-layer chromatography was used in both the oxidation and reduction steps to ensure that each reaction ran to completion.
During the halogenation reactions of 1-butanol, 2-butanol, and 2-methyl-2-propanol, there is a formation of water from the OH atom of the alcohol, and the H atom from the HCl solution. The OH bond of the alcohol is then substituted with the Cl atom. Therefore all of the degrees of alcohol undergo halogenation reactions, and form alkyl halides as products. This is because the functional group of alkyl halides is a carbon-halogen bond. A common halogen is chlorine, as used in this experiment.
The purpose of this experiment was to synthesize the Grignard reagent, phenyl magnesium bromide, and then use the manufactured Grignard reagent to synthesize the alcohol, triphenylmethanol, by reacting with benzophenone and protonation by H3O+. The triphenylmethanol was purified by recrystallization. The melting point, Infrared Spectroscopy, 13C NMR, and 1H NMR were used to characterize and confirm the recrystallized substance was triphenylmethanol.
The Purpose of this experiment is for the students to learn how to use sodium borohydride to reduce benzil to its secondary alcohol product via reduction reaction. This two-step reaction reduces aldehydes by hydrides to primary alcohols, and ketones to secondary alcohols. In order for the reaction to occur and to better control the stereochemistry and yield of the product, the metal hydride nucleophile of the reducing agents such as LiH, LiAlH4, or NaBH4 must be carefully chosen. Being that LiAlH4 and NaBH4 will not react with isolated carbon-carbon double bonds nor the double bonds from aromatic rings; the chosen compound can be reduce selectively when the nucleophile only react with
Before the start of this experiment, the theoretical yield was calculated. Based off the data, it was found that the limiting reagent is 3-nitrobenzaldehyde. The theoretical yield is determined by relating the moles of the limiting reagent to the moles of the anticipated product by a ratio obtained from the overall equation. The theoretical yield was calculated to be 1.3 g. However, the actual yield obtained was greater than the theoretical yield; in other words, the actual mass of the product was higher than the theoretical mass. This led to an abnormally high yield of 320% and an impure product.
The objective of this laboratory experiment is to study both SN1 and SN2 reactions. The first part of the lab focuses on synthesizing 1-bromobutane from 1-butanol by using an SN2 mechanism. The obtained product will then be analyzed using infrared spectroscopy and refractive index. The second part of the lab concentrates on how different factors influence the rate of SN1 reactions. The factors that will be examined are the leaving group, Br versus Cl-; the structure of the alkyl group, 3◦ versus 2◦; and the polarity of the solvent, 40 percent 2-propanol versus 60 percent 2-propanol.
After 10 minutes the reaction liquid was separated from the solid using a vacuum filtration system and toluene. The product was stored and dried until week 2 of the experiment. The product was weighed to be 0.31 g. Percent yield was calculated to be 38.75%. IR spectra data was conducted for the two starting materials and of the product. Melting point determination was performed on the product and proton NMR spectrum was given. The IR spectrum revealed peaks at 1720 cm-1, which indicated the presence of a lactone group, and 1730 cm-1, representing a functional group of a carboxylic acid (C=O), and 3300cm-1, indicating the presence of an alcohol group (O-H). All three peaks correspond with the desired product. A second TLC using the same mobile and stationary phase as the first was performed and revealed Rf Values of 0.17 and 0.43for the product. The first value was unique to the product indicating that the Diels-Alder reaction was successful. The other Rf value of 0.43 matched that of maleic anhydride indicating some
Using SN1 reaction mechanism with hydrochloric acid, t-Pentyl alcohol was converted to t-Pentyl chloride in an acid catalyzed reaction. The reaction took place in a separatory funnel designed to separate immiscible liquids. The crude product was extracted by transferring a solute from one solvent to another. The process of washing the solutions by phase transfer was used in order to remove impurities from the main solvent layer. Finally, the crude product was dried with anhydrous Calcium chloride and purified once more by simple distillation technique.
The purpose of this experiment is to distinguish the relationships between reactants and products, in addition to expanding on concepts such as single displacement reactions, mole ratio values, moles to mass, theoretical yields, limiting reactants, excess, stoichiometric relationships and percentage errors.
This experiment was designed by conducting a substitution reaction to construct a complex compound (2-methylphenoxyacetic acid) from two simple parts; also known as synthesis - converting simple molecules into more complex molecules. A purification technique known as crystallization was used to purify the product. Suction filtration was used to filter out the product. The experiment was completed over a three-day experimental period.
A unimolecular nucleophilic substitution or SN1 is a two-step reaction that occurs with a first order reaction. The rate-limiting step, which is the first step, forms a carbocation. This would be the slowest step in the mechanism. The addition of the nucleophile speeds up the reaction and stabilizes the carbocation. This reaction is more favorable with tertiary and sometimes secondary alkyl halides under strong basic or acidic conditions with secondary or tertiary alcohols. In this experiment, the t-butyl halide underwent an SN1 reaction. Nucleophiles do not necessarily effect the reaction because the nucleophile is considered zero order, (which makes it a first order reaction.) The ion that should have the strongest effect in an SN1 reaction is the bromide ion. The bromide ion should be stronger because it has a lower electronegativity than chloride as well as a smaller radius.
The purpose of this experiment is to examine the reactivities of various alkyl halides under both SN2 and SN1 reaction conditions. The alkyl halides will be examined based on the substrate types and solvent the reaction takes place in.
SN1 reactions are considered unimolecular nucleophilic substitution mechanisms and are a first-order process. Meaning that the reaction forms a carbocation intermediate and that the concentration of the nucleophile does not play a role in the rate-determining step, which is the slowest step in the reaction. All of the SN1 reaction mechanisms in this procedure can react two different ways. The expected mechanism for these reactions would be that the carbocation would react with the weak nucleophile nitrate, attaching the nitrogen to the positively charged carbon. However, while nitrate is the intended nucleophile in all of the reactions, it is a poor nucleophile. The ethanol used in this reaction is a polar protic ionizing solvent,
In this experiment, the purpose was to create and observe the effects of a S_N 1 reaction. Silver nitrate was dissolved in ethanol. The nitrate ion is a decent nucleophile, and ethanol is a fairly powerful solvent. The difference in a SN1 reaction than an SN2 reaction is that a carbocation is formed. The leaving group wants to leave on it’s own, causing a multi-step synthesis.
The purpose of this lab was to discover the effects that an alkyl group and solvent have on the rate of SN1 and SN2 reactions. Two separate mechanisms can be used to perform the nucleophilic substitution of alkyl halides: SN1 and SN2. A SN1 reaction, or unimolecular displacement, is a 1st order, nucleophilic substitution that involves two steps. The rate law for this reaction, Rate = k[Rx], doesn’t include the nucleophile in it.1 These two step reactions have a carbocation intermediate. SN1 reactions work best when the central carbon has as many bulky groups surrounding it as possible. These substituents increase the possibility of the carbocation intermediate forming by increasing the steric strain of the molecule. This idea is which causes a carbocation intermediate to develop in reactions of secondary or tertiary alkyl halides, and a primary alkyl halide to not be able to go through a SN1 reaction. The carbocation intermediate that forms is a sp2 carbon that allows the nucleophile to attack from both sides of the molecule. If neither attack is favored, they both occur equally, making it a racemic mixture. The solvent of choice for the SN1 reactions are both polar and protic, because a solvent that will not react with the carbocation intermediate is needed, since this will give an unwanted product. In polar protic solvents you get a hydrogen atom that is very highly polarized since it is attached to an electronegative atom, because of this it can interact